package org.apache.solr.analysis;

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.util.Arrays;
import java.util.HashSet;
import java.util.Map;

import org.apache.commons.codec.language.bm.Languages.LanguageSet;
import org.apache.commons.codec.language.bm.NameType;
import org.apache.commons.codec.language.bm.PhoneticEngine;
import org.apache.commons.codec.language.bm.RuleType;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.phonetic.BeiderMorseFilter;

/**
 * Factory for {@link BeiderMorseFilter}.
 * 
 * <pre class="prettyprint" >
 * &lt;fieldType name="text_bm" class="solr.TextField" positionIncrementGap="100"&gt;
 *   &lt;analyzer&gt;
 *     &lt;tokenizer class="solr.StandardTokenizerFactory"/&gt;
 *     &lt;filter class="solr.BeiderMorseFilterFactory"
 *        nameType="GENERIC" ruleType="APPROX" 
 *        concat="true" languageSet="auto"
 *     &lt;/filter&gt;
 *   &lt;/analyzer&gt;
 * &lt;/fieldType&gt;
 * </pre>
 * 
 */
public class BeiderMorseFilterFactory extends BaseTokenFilterFactory {
	private PhoneticEngine engine;
	private LanguageSet languageSet;

	public void init(Map<String, String> args) {
		super.init(args);

		// PhoneticEngine = NameType + RuleType + concat
		// we use common-codec's defaults: GENERIC + APPROX + true
		String nameTypeArg = args.get("nameType");
		NameType nameType = (nameTypeArg == null) ? NameType.GENERIC : NameType
				.valueOf(nameTypeArg);

		String ruleTypeArg = args.get("ruleType");
		RuleType ruleType = (ruleTypeArg == null) ? RuleType.APPROX : RuleType
				.valueOf(ruleTypeArg);

		boolean concat = getBoolean("concat", true);
		engine = new PhoneticEngine(nameType, ruleType, concat);

		// LanguageSet: defaults to automagic, otherwise a comma-separated list.
		String languageSetArg = args.get("languageSet");
		if (languageSetArg == null || languageSetArg.equals("auto")) {
			languageSet = null;
		} else {
			languageSet = LanguageSet.from(new HashSet<String>(Arrays
					.asList(languageSetArg.split(","))));
		}
	}

	public TokenStream create(TokenStream input) {
		return new BeiderMorseFilter(input, engine, languageSet);
	}
}
